Optimized File Writer

File writes are handled efficiently to reduce allocation overhead and keep logging predictable even in busy applications.

This is especially useful for:

• HTTP APIs
• background workers
• queue consumers
• long-running services
• applications with frequent structured logs

Example usage:

package main

import (
	"log/slog"

	"github.com/netlifeguru/logger"
)

func main() {
	closer, err := logger.Init(logger.Config{
		Dir:            "./logs",
		TerminalOutput: false,
		MinLevel:       slog.LevelInfo,
	})

	if err != nil {
		slog.Error(err.Error())
	}

	defer closer.Close()

	slog.Info("file logging enabled",
		slog.String("service", "api"),
		slog.String("environment", "production"),
	)
}

Example file output:

{
  "time": "2026-05-11T12:56:31.879333+02:00",
  "level": "INFO",
  "msg": "file logging enabled",
  "service": "api",
  "environment": "production"
}

The file writer is optimized for:

• structured JSON output
• repeated log writes
• concurrent application workloads
• reduced allocation overhead
• predictable file rotation behavior

For applications where logging is part of a hot path, this keeps persisted logs useful without introducing unnecessary runtime pressure.